Airplane-rib



I. W. RAPP AND J. VANORIO.

AIRPLANE RIB.

APPLICATION FILED FEB. 27. 1919.

Patented 0ct2f6,1920.

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Elma/nag UNITED STATES PATENT OFFICE.

JOHN W. RAPP AND JOSEPH VANORIO, OF COLLEGE POINT, NE'W'YORK; SAID VANORIO ASSIGNOR TO SAID RAPI.

AIRPLANE-BIB.

Specification of Letters Patent.

Patented Oct. 26, 1920.-

Original application flled January 19, 1918-, Serial No. 212,7 85. Divided and this application filed February 27, 1919. Serial No. 279,558.

To all whom it may concern:

Be it known that we, JOHN W. Barr and JOSEPH VANORIO, citizens of the United States, and residents of Colle e Point, county of Queens, and State of ew York, have invented certain new and useful Improvements in Airplane-Ribs, of which the following is a specification.

This invention relates to improvements in airplane ribs and is a division of the subject matter included incur application Serial No. 212,785, filed on the 19th-day of Januarv,1918.

n airplane ribs and particularly in metallic airplane ribs, it is desirable to'procure the maximum resistance to strains of compression, tension and torsion with a minimum ofweight, and in such metallic airplane ribs it is desirable because of the homogeneity of the structure to produce such a'rib made of a single pieeeof sheet metal.

By our invention, we are enabled in a rib formed from a single piece of sheet metal to take advantage of the great resistance to bending and torsional strains afforded by top and bottom channel or hook-shaped lon itudinals and a Web which has struts in wh1ch the maximum amount of column action of the metal thereof is procured. To these ends, we have produced an airplane rib formed from a single strip or blank of sheet metal cut to provide longitudinals comprising top and bottom longitudinallyfolded portions of substantially channel or hook-shaped cross section, and diagonally arranged struts of substantially triangular cross-section intermediate saidtop and bottom longitudinally-folded ortions, the said struts preferably being em ossed to one 'side of a vertical plane passing through the axis through which strains of compression will pass when the rib is in use and having the free flanges of such struts bent to the opposite side of such a plane. Such a plane will coincide with the vertical-disposed connecting portion between the struts and longitudinal and will pass through the opposite sides of the strut. A maximum of column action of the metal of the strut will thus result.

Other objects of m invention will be in part obvious from t e annexed drawings and in part indicated in connection there lar marginal frame;

this invention, drawings depicting a pre-' ferred form have been annexed as a part of this disclosure, and in such drawings like characters of reference denote corresponding arts throughout all the views, of whic Figure 1 is a side elevation of a rib for ,aerofoil frames embodying my invention and connected at opposite ends to the t ubu- Fig. 2 is an enlarged fra entary view in side elevation of a portion of the rib shown in Fig. 1;

Fig. 3 is a section on the line 3-3 of g. 2; 1g. 4 1s a sectlon on the line 4-4 of' Fig. 2; and

Fig. '5 is a section similar to Fig. 4 of a modified form of rib, in which the embossing and bendin are in the opposite direction from that s own in Fig. 4.

Referring now to these drawings, and particularly to Fig. 1 1 indicates a rib which is formed from a blank of sheet metal indicated by dotted lines 2, which blank is suitably trimmed to aerocurve shape and is longitudinally bent or folded at its top and bottom marginal edges to produce ongitudinals comprising channel or. hook-shaped folded portions 3 and 3' re spectively which will afiord considerable resistance to bending and torsional strains. The web ortion intermediate such longitudinallyolded portions is partially cut away to provide diagonally disposed struts 4.- and interstrut openings 4: and a verticall -disposed connecting or rim portion 5. Bee of the said diagonally disposed struts 4, in order'to-provide stiffness and rigidity, has the entire metal of such strut bent latertit ally into a form substantially triangular in cross-section. This bending of the metal greatly increases its column action over other constructions and thus increases the resistance of the metal of. the strut to strains of compression and when struts of this character are used in combination with the substantially tubular horizontally'folded portions, a large measure of rigidity is procured in the rib. We have been enabled to further increase the rigidity of the rib, however, and to procure the maximum amount of column action for the metal of such struts, by not only bending all the metal into such triangular cross-section but by also bending such metal so as to extend on opposite sides ofa vertical axis through which strains of compression will be applied when the rib is in use. To this end, therefore, we have embossed a part of the metal of such strut portions and preferably the central portion to one side of a vertical plane passing through the said axis through which strains of compression will pass when the rib is in use and have bent the free .flanges of such struts so as to extend to the strength, rigidit and factor of safety of the rib are materia 1y increased.

It is apparent, therefore, that an aerofoil frame when a series of ribs of this character are employed, parts 6 and 7 of which are shown, it will, owing first to the increase in column action procured by the bending of all the metal of the diagonally disposed struts into a shape triangular in cross-section, second, to the further increase in column action due to the combined embossing and bending of the metalof the struts to opposite sides of the axis through which strains of compression will be applied, third, to the resistance to bending afforded by the channel-shaped longitudinals, have, in proportion to its weight, greatly increased rigidity and strength over any rib of equal weight and inherent tensile strength of metal, and will combine the advantages of homogeneity of structure with great strength.

Having described our invention, We claim:

1 A rib for aerofoils comprising, a single strlp of sheet metal embodying longitudinals comprising top and bottom longitudinally folded portions substantially channel-shaped in cross-section,. formed by folding the upper and lower edges of a blank of metal longitudinally and an intermediate web portudinally and an intermediate web portion having diagonally disposed struts and interstrut openings, the metal of each of the struts being bent laterally from edge to edge into a shape substantially triangular in cross-section with a portion of such triangular Web on opposite sides of a plane passing vertically through the axis through which strains of compression willbe applied when the said rib is in use.

3. A rib for aerofoils comprising a single strip of sheet metal embodying'longitudinals comprising top and bottom longitudinallyfolded portions substantially channel-shaped in cross-section, formed by folding the upper and lower edges of a blank of metal longitudinally, an intermediate web portion havingdiagonally disposed struts, in-

terstrut openings and connecting rim strips,

the metal of each of such struts being embossed at its apex portion to one side of a plane passing through the said connecting rim strips and having the free flanges of such struts bent to the opposite side of such a plane.

4. A rib for aerofoils comprising a single strip of sheet metal embodying longitudinals comprising top and bottom longitudinally-folded portions substantially channel-' shaped in cross-section, vformed by folding the upper and lower edges of ablank of metal longitudinally, an intermediate web portion having diagonally disposed struts, interstrut openings and connecting rim strlps, the metal of each of such struts being embossed at its apex portion to one side of a plane passing through the said connecting rim strips and having the free flanges of such struts bent to the opposite side of such a plane, said embossing of the apex and bending of the flanges being to a substantially equal extent on opposite sides of said plane so that said-plane will symmetrically cut opposite sides of the triangular struts.

5. An aerofoil frame embodying a suitably disposed metallic marginal flange and a series of ribs secured thereto at opposite ends each comprising a single strip of sheet metal having longitudinals formed from top and bottom longitudinally folded portions substantially channel-shaped in cross-section, formed by folding theupper and lower edges of a blank of metal longitudinally and an intermediate Web portion having diagonally disposed struts and interstrut openings, the metal of each of the struts being bent laterally from edge to edge into a shape substantially triangular in cross-section.

6. An aerofoil frame embodying a suitably disposed gnetallic marginal frame and a series of ribs secured thereto at opposite ends, each comprising a single strip of sheet metal having longitudinals formed from top and bottom longitudinally folded portions substantially channel-shaped in cross-section, formed by folding the upper and lower edges of a blank of metal longitudinally, an intermediate Web portion having diagonally disposed struts, interstrut openings and connecting rim strips, the metal of each of such struts being embossed at its apex portion to one side of a plane passing through'the said connecting rim strips and having the free flanges of such struts bent to the opposite side of such a plane.

In Witness whereof, We have signed our names to the foregoing specification in the 25 presence of two subscribing Witnesses.

JOHN W. RAPP. JOSEPH VANORIO.

Witnesses:

HELEN V. WHIDDEN, STALLO VINTON. 

